To solve this kind of question, check each option for a smaller word that means almost the same thing as the full word and whose letters appear in the same left-to-right order within the larger word, even if other letters sit between them.
Working through "respite", letter by letter: R, E, S, P, I, T, E. Selecting R, then E, then S, then skipping P and I to reach T, produces the sequence R-E-S-T, which spells "rest". Respite itself means a brief break or a period of relief from something tiring or stressful, which is essentially what rest means too. That gives a matching pair, rest hidden inside respite, both in order and in meaning, exactly what defines a kangaroo word.
The other three words do not offer this. "Sleep", "Walk", and "Talk" are each short everyday words, and searching through their letters does not reveal a smaller synonym spelled out in sequence. Because "respite" is the only option that hides a same-meaning shorter word, "rest", inside its own spelling in the correct order, the answer is option 2, respite.